Toll-telephone switching apparatus



v H. M. FRIENDLY. TOLL TELEPHONE SWITCHING APPARATUS. APPLICATlON FILED JUNE 17- 1915.

1,370,300, Patented Mar. 1, 1921.

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UNITED STATES PATENT OFFICE.

HERBERT M. FRIENDLY, 0F PORTLAND. OREGON.

TOLL-TELEPHONE I SWITCHING APPARATUS.

Specification of Letters Patent.

Patented Mar. 1, 1921.

Application filed June 17, 1915. Serial No. 34,666.

junction with independent lines adapted to be connected with said toll lines.

Due to the conditions met in practical telephonic operations varying in electrical, structural and operative details, due to manifold reasons, the application of my invention to the various practical cases will be different. However, such varied adaptations and applications belong to and are subordinate to my invention. It being impossible to devise apparatus for carrying out my invention practically that ma be applied universally to all conditions, I ave chosen one application and organization, as shown and describedhereim-of my invention to elucidate its principles, construction and combination. It is manifest that features of my invention can thus be employed as an amplification orwithout its adoption as an entirety, and that the details of con- I struction and operation can be varied and applied within wide limits without departingfroin its scope by those skilled in the art to which it belongs.

An object of this invention is to reduce themanual efi'ort necessary in methods heretofore employed in establishing telephonic circuits and to facilitate the interconnection of toll lines remotely under the more or less automatic control of an operator attendant at a station along one or more of these lines.

Further,,to permit signaling along an en tering toll line in its normal manner and to also signal on a connected-toll line at the will of a remote operator controlling the interconnection. objects.

In the accompanying drawings:

Figure '1 is a diagrammatic conventional representation of two toll lines arranged for interconnection.

' Fig. '2 shows the essential features of a common form of cord interconnecting pair There are many other commonly used for connecting lines between spring jacks.

Referring to the figures in. detail:

Fig. 1, which shows two toll lines arranged for interconnection, has a station A on a toll line 1; a station C on a toll line 2; a station B on toll line 1 and toll line 2. A relay R4 at. station B is so disposed that it will interconnect lines 1 and 2 in response to manipulation and resultant current of predetermined character from station A or station C. The normal uses of line 1, between station A and station B, and vice versa, and between station C and station B, and vice versa, are not operatively effected. The circuit details of stations A and B are similar. The reference letters used are the same in referring to equivalent parts at both stations, with the exception that in referring to parts at station C a prime is added. At station A, a battery, or other source of current B1, has its positive pole grounded, the free end, therefore negative terminal, being adapted to project negative or minus current. A battery B2 has its negative pole grounded, its free terminal therefore being adapted to project positive or plus current.

At station C a battery Bl" has its negative pole grounded and its free pole is therefore adapted to project positive or plus current.

A battery B2 at station Chas its positive pole grounded and its free pole is therefore adapted to project negative or minus current. Relays R1, R1 and R4 are polarized relays and therefore responsive to directional current. The designations on the pole pieces of these relays indicate'relative positions of these relays under application of actuating current, and will be referred to hereafter. The drawings show the relays in their normal position, with circuits unenergized.

At station A, there are two springjacks designated J1,.and J2. The tip and ring springs of these jacks are cohnected to line 1. A signal device D2 associated with J2 is connected to line 1 by wa of contacts 10-11 and 12 13 of.relay B2. A signal device D1 associated with J1 is in a local circuit of relay R1 and is adapted to have signaling current applied to it from source Z upon the operation of R1 by way of contacts 2-3 and 5;-=-6. Relay R2 is adapted to disassociate signal device D2 upon said relay being energized and actuated by-current cuits is for normalfunconnected use.

such as will flow in a circuit'from the sleeve conductor J2 through the sleeve conductor of plu P1 to ground as shown 'n 2. Relay 3 is adapted to be energized an actuated by current such as will flow in a circuit from the sleeve conductor of J1,

through the sleeve conductor of plug as P1 to ground as shown in Fig. 2. A controlling key is is adapted to cause plus current to be projected in parallel over the line wires of line 1 by way of its contacts 18-19 and retardation coil 11. In the normal position of key It a circuit may be traced from a central point of retardation coil r1 to contacts 19-20; through contacts 17-18; through relay R1, to ground G1. The. operation of plied to D1 as described and line 1 simultaneously, through contacts 1-2-3 and 4-5-6. It will also cause relay R2 to actuate disassociating D2 by reason of the closing of contacts 7-8. This description in reference to station A may be applied to station C by hearing in mind that a prime is added to referenge designations.

Relay R4 derives current between the lines 1 and 2 through the central points of retardation coils T2 and r3. Signal devices S1 and S2 will res 0nd to currents applied to springjacks 3 and J4 respectively and are disassociated therefrom upon inserting a plug as P1 into said respective springj acks. v

Assuming that an operator at station A desires to signal station B, a plug as P1 will be inserted into J2 and signaling current applied by depressing key 101. ignaling current from source as Z1 will then be applied along line 1 to springjack J3 and to signal devlce S1. Upon the operator at station B responding as by the insertion of a plug as P1 into said springjack J3 and manipulating the cord listening key 102, said 0 erator will be able to communicate teleonically with the operator at station A.

be same relative operation would enable an operator at station C to insert plug as P1 into springjack J2 and cause signal device S2 at station D to displafi and enable an operator. at said station to respond telephonically by inserting plug as P1 into springjack J4, upon manipulation of key k2 as before described. 1 I

The above described operation of the following will describe the use of the cir-' cuits as used interconnected under remote control:

Assuming that an operatorat station A desires to signal and communicate telephonically with an operator at station C, the o '70 erator at station A will insert plug as 1 into springjack J2, which will disassociate signal device D2, as previously described and enable the operator, through cord listening key 102 and operators circuit associated with terminals 26 and 27, to listen ii" on and along line l. If line 1 is found d sengaged, the operator will withdraw plug 1 from springjack J2 and insert said plug into springjack J1." As previously described, this will cause relay R3 to become gperated. The operation of relay R3 incidentally closes its contacts 14-15, which will ground the free terminal of relag R2, thereby disassociating signal device 2 as previously described. It will also cause its contacts 18-17 to open, opening the circuit of relay R1 between the center of retardation 0011 1'1 and ground G1. Simultaneously it will close contacts 16-17, which will apply minus current from battery B1 through contacts 20-19; to center of retardation coil 1'1; along line 1; through retardation coil 72 differentially to its central point; thence through relay R4, actuating it in its indicated plus direction; thence to the central point of retardation coil r3; thence differentially through said retardation coil along line 2 to retardation coil 11; thence differenthence to ground G1. In this condition of circuits and apparatus (bearing in mind that relay R1 is in its normal indicated minus direction), R 1: is in its operated indicated plus direction and relay R1 is in its normal indicated minus direction, a telephonic connection may be traced from operators listenin key 102 through tip and ring conductors o plug P1; through tip and ring conductors of springjack J1; thence along line 1 through contacts 21-22 and 23-24 of relay R4; thence through condensers C1 and C2 to line 2; thence to springjacks J1 and J2 in multiple. The operator at station A can now listen along line 2 to ascertain if it is engaged. If it is not engaged, the operator can signal along line 2 independently of line 1 and also signal station C through its signal device D1 by the depression of key it. Each depression of key It will open the circuit of relay R1 at contacts 19-20. It will simultaneously apply plus current'from battery B2 by way of contacts 18-19 to center of retardation coil T1 and over the same path as previously described, leaving the center of retardation :coil 11, through contacts 19-20'; through contacts 17 -18; through relay R1 to ground G1 (bearing in mind that there are no plugs in springjacks J1 and J2) actuating relay R1 in the indicated plus direction. lVhen relay R1 is in its operated position, signaling current from source Z will be applied through contacts 12-3 and 4-56 along line 2, causing bridged signal devices S5 and S6 to operate, and it will also apply signaling surrent to signal device Dl associated. with springjack J1. The closing of contacts 78 will cause relay R2 to operate, disassociating signal device D2. The current along line 1 through relay R4 and along line 2, as previously traced, is reversed in direction by the said depression of key 7:. This will cause relay R4: to be pulled against its normal stop indicated minus, thus disassociating line 1 from line 2 at contacts 2122, 2324, during the duration of plus current emanating from battery B2. In other words, during the time relay R1 is in its operated position in response to plus current from battery B2 applied through the agency of key 70, relay R4 will be pulled against its normal stop indicated minus. It will be observed that the signal device displayed at station C is D1 associated with springjack J1 and not D2 as would be displayed were an operator at station B signaling station C in the normal manner from springjack J4 (or station S5 for instance, signaling station C). The operator at stat-ion C will respond by inserting plug as P1 into sprin jack J1 companion to signal device D1. elay R3 will actuate by obtaining ground at its free terminal through sleeve conductor of springjack J1 and of plug P1. The operatlon of relay R3 will apply plus current from battery B1 through contacts 1617'; through contacts 2019 to the center of retardation coil 11, meeting minus current from battery B1 previously described. Thus battery B1 will be acting serially over the path previously described, but instead of reaching ground G1 directly at station C, it reaches ground G1 through battery B1 in series. The resultant current in the circuit will be increased in strength due to the increased voltage introduced, but since the direction of flow has not been changed there will be no dependent apparatus relations changed. Should the operator at station A at this juncture remove the plug P1 from springjack J1, minus battery applied as described. by virtue of relay R3 being operated, will be disassociated and simultaneously ground G1 will be applied through relay R1 at contacts 17-18, but since the current passing through relay R1, emanating from battery B1, is of a plus direction, its effect on relay R1 will be to pull it against its normal stop indicated minus and thus produce no operative effect. Relay R4 will not be operatively efl'ected by this change and will remain operative in its indicated plus direction. It will thus be seen that should operator at station A have called station C in response to the request of a station S3, for instance, 1l)0I1 the response of the operator at'station the operator at station A can Withdraw the said switching plug, and thereby leave the line, and "the lines will remain interconnected by virtue of the plug being inserted into spring-jack J1, as described. Telephonic service may then be held between any station on line 1 and station C or any station along line 2 until the operator at station C withdraws the switching plug from springjack J1, the interconnection of the lines being now under the control of operator at station C after the plug has been removed from springjack J1 at station A. 1

If the operator at station A in the previous description had signaled by prearranged code a station S5, for instance, in place of station C, signal D1 would have become displayed at station C as previously described, but the operator at said station U would not necessarily respond, but said operator would know'that such a station S5 was called, and furthermore that the signal emanated from station A, as no station on line 2 would be enabled to cause signal D1 to be displayed.

It will be observed in the above that currents along and between the lines 1 and 2, that will actuate either relay R1 or R1 to cause them to operate in an indicated plus direction, will cause relay R4 to pull toward its normal indicated minus direction and vice versa. Therefore, whenever a signal is caused to display along a line remote to the operator controlling said signal, the relay R4 will simultaneously return to its normal'position, incidentally disassociating the lines 1 and 2 telephonically. Further, an operator at station A, for instance, signals independently along line 1 and line 2, at will, and an operator at station C is similarly enabled to signal independently along line 2 or line 1. The same code of signals may therefore be used for stations along line 1 and along line 2 without confusion. It is not essential that station A shall be a terminal station, but it may be placed at any point along or on a leg off line 1. Similarly, it is not necessary that station 0 shall be a terminal station, 'but it may be placed at any point along or on line 2. That is to say,

vthe apparatus at stations A and B respectively, may be placed contiguous to the apparatus at station B. Assuming the station A were placed on the premises with station B, the ringing on line 1 would be from A now at the right hand terminus in place of the ringing coming from the left as shown in the drawing, on through connections. This location of the stations is, of course, a matter of choice, convenience or line arrangement. 7

The descri tions for interconnection have been with re ation to station A calling station C. By bearing in mind that the prime is added to all designations of equipments and parts at station 0, the description above for station A may be applied to a reciprocal connection from station C to station A, or any station along the line 1.

Spring'jacks J1 and J2, and J1 and J2 are shown as individual springjacks.- It is possible to place a plurality of jacks in multiple relation with each of these said jacks to enable operators at various remote positions at. the respective stations to get similar access.

It is not essential that current for actuating the relays R1, R4 and R1 traverse both limbs of the lines 1 and 2 in a derived or parallel relation. The said relays and dependent functions will be operative in response to currents over one limb only, which I would be the case if, for example, the upper terminals of the retardation coils 1'1, r2, 1'3 and T1 were disconnected from the upper limb of the line.

The various points of novelty hereinbefore mentioned, described and shown in the accompanying drawings are by way of illustration only and therefore by no means exhaustive.

Having thus described my invention, what I claim as new and desire to secure by United States Letters Patent is:

1. A' telephone system comprising a near line in permanent series relation with a remote line, said lines being permanently paired at an intermediate inter-connecting station, two springjacks associated with the near line, a plug ended switching cord, one of said springjacks when, connected with said plug adapted to establish normal connection with said near line, and means at the intermediate station responsive to insertion of said plug in the other of said springjacks for connecting said remote line together with said near line. 1

2. A telephone system comprising a near line normally in series relation with a remoteline, two springjacks associated with the near line, a plug ended switching cord, sources of current oftwo characters, one of said springjacks when connected with said plug adapted to establish normal communication with said near line; and means responsive to said currents when said plug is inserted in the other of said s ringjacks to establish at will signaling and communication with said remote line.

3., A telephone system including a near line normally in series relation with a remote line ada ted to be interconnected under control 0 either a station on said near mote line; a switching plug at each of said stations adapted -to be used with said spring- "jacks at said stations; sources of current of two characters at each of said stations; suitable apparatus at said stations and at a station common to said near and said remote lines, means responsive to the application of said plug to one of said springjacks to establish connection to its near line, said apparatus being res onsive to the application-of said plug to t e other of said springjacks to cause the two said lines to become interconnected and to become disconnected upon the removal of said plug; means for changing the character of current ap lied to line at said stations on said near an said remote line whereby signaling may be efsaid remote line at sald station on said remote line; a switching plug at each of said stations ada ted to be used with said springjack at said stations; sources of current of two characters at-each of said stations; suitable apparatus at a station common to said nearand remote lines; means responsive to the application of; said plug to one of said springacks to establish connection to its near line, said apparatus being responsive to the application of said plugto the other of said springjacks to cause the two said lines to become interconnected and to becrlime disconnected upon the removal of said p ug. r

a 5. A telephonesystem including two telephone lines, an interconnection station between said two lines, a connecting station on each line, and a polarized relay under primary control of current applied at a remote station on one of said lines, means controlled by the operator at a station to apply current from said station to the relay toefi'ect the actuation of said relay causing saidlines-to become connected, the deenergization of said relay causing said relay to assume normal position with lines unconnected...

6. Apparatus adapted to control the interconnection oflines remotely by the employment of currents-of different directions respectively; two lines; acontrol station on each lme; an interconnecting pomt; means at said controlling stations for efi'ecting the changes of current direction; sources of current of two polarities; a relay at said interconnection point responsive to said changes in current direction that will cause lines to be interconnected or independent in conformity therewith; apparatus at the sta tion on the remote line adapted to project signaling current along said remote line responsive to said directional currents under control of said station on the other line.

7. A telephone system comprisin two substation telephone lines, a first station on a first of two lines adapted to be connected together, a second station on a second of said two lines, a third station common to both said lines, a source of signaling current; a first polarized relayrat said third station adapted to connect said lines together upon actuation, a second polarized relay at said second station responsive to currents of opposite direction to that which will actuate said first polarized relay, said second polarized relay adapted to project signaling currents along said second line upon actuation; means at said first station to project current of polarity to actuate said first polarized relay, a pole-chan 'ng switch at said first station adapte to change polarity of said current projected.

8.- A telephone system including two substation telephone lines, a first station on a first of two lines adapted to be connected together, a second station on a second of said two lines, a third station common to both said lines, a source of signaling current, a first polarized relay at said third station adapted to connect said lines together upon actuation, a second polarized relay at said second station responsive to currents of opposite direction to that which Wlll actuate said first polarized relay, said second polarized relay adapted to project slgnaling currents along said second line upon actuation, a means at. said first station to project current of polarity to actuate said first polarized relay, a polechanging switch at said first station adapted to change polarity of said current projected, the manipulation of said switch causing said first polarized relay to returnto normal position and cause said second polarized relay to actuate.

9. A telephone system including two subs station lines, a first station on a first of two lines adapted to be connected together, a second station on a second ofsaid two lines, a third station common to both said lines, a source of signalin currentja first polarized relay at said third tion, a second polarized relay at said second station responsive 'to currents of opposite direction to that which will actuate said first polarized relay, said second polarized relay 7 ments of said springjacks so dispose station. adapted; to connect said lines together upon actuaadapted to project signaling currents along said second line upon actuation, a means at said first "station to project current of polarity to actuate said first polarized relay, a pole-changing switch at said first station ada ted to change polarity of said current pro ected, the return to normal of said switch causing said first polarized relay to again actuate and said second polarized relay to return to its normal position.

10. A telephone system including two substation telephone lines, a first station on a first of two lines adapted to be connected together, a second station on a second of said twolines, a third station common to both said lines, a first polarized relay at said third statign adapted to connect said lines together upon actuation, a second polarized re ay at said second station responsive to currents of opposite direction to that which will actuate said first polarized relay, said second polarized relay adapted to pro ect signaling currents along said second line upon actuation, a source of signaling current at said second station, a means at said first station to project current of polarity to actuate said first polarized relay, sources of current of two polarities at said first station, a pole-changing switch at said first station ada ted to change polarity of said current pro ected.

11. A telephone system including a near line and a remote line, means adapted to interconnect a near line with a remote line including two springjacks associated with the near line, a switching plug, sources of current of 'two characters, one of said s ringjacks in combination with said plug a apted to establish connection with said near line, and means -whereby the other of said springjacks in combination with said plug establishes connection with and signals along said remote line over said near line.

12. The combination of a first and a second line ot; a first polarized relay at a point common to said two lines, a polarized relay for each line, sources of current of two polarities, two springjacks in normal multiple relation as regards the two limbs of said first line. a plug ended cord, aux'ilia tile;

a incidental to the insertion of said switching plug into a'first of said springjacks current. of proper direction will actuate said first relay at said common point and thereby cause said lines to become telephonically interconnected while; the insertion of said switching plug into the second of said springjacks wi I not cause current to be projecte to actuate said first relay, a pole changing switch adapted to change the direction of said current flowing along said lines, when said plug is inserted into the said first s ringjack, in order to actuate said second po arized relay on said second line adapted to cause signaling current to be projected along said second line and incidentally cause said first relay to disassociate said lines telephonically.

13. In combination with a first line and a second line adapted to be interconnected, a first and a second signaling device, a first and-a second springjack respectively associated with said first and said second signal device, current sources of two characters, an agency for applying same to said lines alternatively, the application of one character of signalingcurrent adapted to cause the first said signal device to display and disassociate said second signal device, the application of the other character of signaling current adapted to interconnect said lines.

'14. A telephone system comprising two subscribers telephone lines terminating at a central interconnecting station, an operator controlled relay having cooperating contacts in which said lines normally terminate for interconnection, an operators connecting stationon each line, said operators stations bein at different exchanges, a subscribers te ephone connected to each line. and means whereby an operator at either line station may operate said relay and may signal a substation on the near line or the far line.

15. A telephone system comprising two subscribers telephone lines terminating at a central interconnecting station, an operators connecting station on each line, said operators stations bein at different exchanges, a subscribers telephone connected to one line, means whereby an operator at either line station may signal any of the other stations, and a relay at the central interconnecting .station having cooperating contacts in which said lines normally terminate for interconnection controlled by either operator for interconnecting the lines.

16. A telephone system comprising two telephone lines terminating at a central interconnecting ooint, relay mechanism permanently associated with said two lines at the interconnecting point and common to said a two lines, an operators station on each'line,

said 0 erators stations being at diflerent switchfioards, a spring jack at each switchboard for the corresponding line, a plug ended cord circuit at each switchboard, means for operating said relay mechanism responsive to the insertion and withdrawal of either' lug for connecting and disconnecting sald lines respectively.

17. A telephone system comprising two subscribers" telephone lines terminating at a central interconnecting station, an opera tor controlled relay having cooperating contacts in which said lines normally terminate for interconnection, an operators connecting station on each line, said operators stations being at different exchanges, a subscribers telephone connected to each line, and means whereby an operator at either line station may operate said relay and may signal a substation on the near or the far line independently. t

18. A telephonev system comprising two subscribers telephone lines terminating at a central interconnecting station, an operator controlled relay having cooperating contacts inv which said lines normally terminate for interconnection, an operators connectmg station on each line, said operators stations being at different exchanges, means whereby an operator at either line station may signal ,on the near line or on the far line and may control the interconnection of said lines at the central station by said relay. I 19. A telephone system comprising two subscribers telephone lines terminating at a central interconnecting station, an operator controlled relay having cooperating contacts in which said lines normally terminate for interconnect-ion, an operators connecting station on each line, said operators stations being at different exchanges, a subscribers telephone connected to each line, means whereby an operator at either line station may signal a substation on the near line or on the far line and may control the interconnection of said lines at the central station by said relay.

20. A telephone system comprising two subscribers telephone lines terminating at a centralinterconnecting station, an operator controlled relay having cooperating contactsin which said lines normally terminate for interconnection, an operators connecting station on each line, said operators stations being at different exchanges, subscribers telephonesconnected to each line, and means whereby an operator at either line station may operate said relay and may signal the substations on the near line or the far line without affecting the signals of the substations on the line not being called.

21. A telephone system comprising two subscribers telephone lines terminating at a central interconnecting station, an operator controlled relay having cooperating contacts in which said lines normally terminate for interconnection, an operators connecting station on each line, said operators stations being at different exchanges, subscribers telephones connected to each line, and means controlled by an operator at either line station for operating said relay and for transmitting current over the near-line to operate a signal of a substation on a far line without operating the substation signals on the near line.

'22. A telephone system comprising two normally telephonically unconnected subscribers telephone lines terminating at a central interconnecting station, an operator controlled relay having cooperating contacts in which said lines normally terminate for interconnection, an operators. connecting station on each line, said operators stations being at different exchanges, subscriber's telephones connected to each line, means including said relay at the central station tontrolled by either operator for interconnecting said lines telephonically at said central station, and means whereby an operator at either line station may signal the substations on the near line or on the far line independently.

23. A telephone system comprising two normally telephonically unconnected subscribers telephone lines terminating at a central interconnecting station, an operators connecting-statien on each line, said operators stations being at different exchanges, a

' relay at the central station having cooperating contacts in which said lines normally terminate for interconnection controlled by either operator for interconnecting said lines telephonically at said central station, and means whereby an operator at either line station may apply ringing current to the far line only for signaling the far line station.

24. A telephone system comprising two normally telephonidally unconnected subscribers telephone lines terminating at a central interconnecting station, an operators connecting station on each line, said operators stations being at different exchanges, relay mechanism at the centralstation controlled by either'operator for interconnecting said lines telephonically at said central station, and means at each line station in-, cluding a source of ringing current controlled by the operator at the other statlon whereby either operator may signal the other line station by applying the local rlngmg current at the station called.

25. A telephone system comprlsmg two subscribers telephone lines terminating at a central interconnecting station, an operators connecting station on each line, said operators stations being at different exchanges, subscribers telephones connected to each line, a relay individual to said two lines at the central station whereby an operator at either line station may interconnect said lines telephonically, and means whereby an operator at either line stat on may signal the substations on the near hne or on the far line, said interconnecting relay being operative to disconnect said line telephonically during the signaling operation.

26. A telephone system comprising two subscribers telephone lines permanently connected at a central interconnecting sta tion, an operators connecting station on each line, said operators stations being at different exchanges, subscribers telephones connected to each line, a source of ringing current associated with each operators connecting station, and means whereby an operator at either line station may connect the local ringing current to the near line to signal the telephones thereon, or apply the ringing current at the other line station to signal the substations on the far line.

I 27. A telephone system comprising two near line or on the far line, or signal the other operator.

28. telephone system comprising two subscrlbers telephone lines terminating at a central interconnecting station, an opera-' tors connecting station on each line, said operators stations being at different exchanges, subscrlbers telephones-connected to each line, plug ended cord circuits at each exchange, a spring-jack for each line at its corresponding operators connecting station, and relay mechanism at the centralinterconnecting station responsive to the connection and disconnection of the plug and jack at either operators station to interconnect and disconnect said lines respectively.

29. A telephone systemcomprislng two subscribers telephone lines terminating at a central interconnecting station, an operators connecting station on each line, said operators stations being'at different exchanges, subscribers telephones connected to each line, means whereby communication may be had between the telephones on each line and their corresponding operators station, and a relay at the central interconnecting station having cooperating contacts in which said lines normally terminate for interconnection controlled from either operators Sta-i tion for interconnecting said lines at the central station.

30. A telephone system comprising a telephone line extending from one operators station to an interconnecting station, a second telephone line extending from the interconnecting station to a third station, and relay mechanism at the interconnecting station controlled over a simplexed circuit from said operators station for interconnecting said lines telephonically.

31. A telephone system comprising a telephone line extending from one operators station to an interconnecting station, a second telephone line extending from the interconnecting station to a third station, and relay mechanism at the interconnecting station controlled over asuperposed circuit from said operators station for interconnecting said lines telephonically.

32. A telephone system comprising two telephone lines terminating at a central interconnecting point, an operatofls connecting station on each line, said operators stations being in different exchanges, a subscribers telephone connected to one line, and a relay at the central interconnecting station controlled over a simplexed circuit of said lines from either operators station for interconnecting said lines at the central station, and means whereby said telephone may be signaled from either ope-rators station.

'33. A telephone system comprising a telephone line extending from one operators station to an interconnecting station, a second telephone line extending from the interconnecting station to a third station, and means including a simplexed circuit whereby the operator at one station may signal on the far line by impresslng ringlng current upon said far line from one of the other stations.

34:. A telephone system comprising a telephone line extending from one operators station to an interconnecting station, a second telephone line extending from the interconnecting station to a third station, and means including a superposed circuit where by the operator at one station may signal on the far line b impressing ringing current upon said far ine from one of the other stations.

35. A telephone system comprising a telephone line extending from one operators station to an interconnecting point, a second telephone line extending from the interconnecting point to a second operators station, said operators stations being at different exchanges, a subscribers telephone connected to one line, and means including a simplexed circuit whereby the operator at one station may signal the subscrlbers telephone on the other line by impressing ringing current upon the subscribers telephoneline from its operators station.

36. A telephone system comprising a telephone line extending from one operators station to an interconnecting station, a second telephone line extending from the interconnecting station to a third station, means including a simplexed circuit whereby the operator at one station may signal on the far line by impressing ringing current upon the said far line from one of the other stations, and means for telephonically disconnecting said lines at the interconnecting station during the transmission of the signal.

37. In a telephone system a telephone line extending from a first operators connecting station to a second station, a second teleohone line extending from the second station to a second operators connecting station, a line jack and a switching jack connected to the first line at the first operators station, a plug ended cord circuit at said first station,

and means whereby when said plug is connected to the line jack connection is established withithe first line and when the plug is'connected to the switching jack connection is extended over the first line to the second operators connecting station.

38. In a telephone system a telephone line extending from a first operators connecting station to a second station, a second telephone line extending-from the second station to a second operators connecting station, a line jack and a switching jack connected to the first line at the first operators station, a plug ended cord circuit at said first station, means whereby when said plug is connected to the line jack, connection is established with the first line, and when the plug is connected to the switching jack connection is extended over the first line to the second operators connecting station, and means whereby the operator at the first station may sigrlial the first-or second lines independent 39? In a telephone system a telephone line extending from a first operators connecting station to a second station, a second telephone line extending from the second station to a second operators connecting station, a line jack and a switching jack connected to the first line at the first operators station, a plug ended cord circuit at said first station, means whereby when said plug to a second operators connecting station, a

line jack and a switching jack connected tothe first line at the first operators station, a plug ended cord circuit at said first station, and means whereby when said plug is connected to the line jack connection is established with the first line and when the plug is connected to the switching jack connection is extended over the first line to they second operators connecting station, and relay mechanism at the central interconnecting station whereby the originating operator may connect and disconnect said lines.

41. A telephone system comprising a telephone line extending from a first operators connecting station to a second station, a second telephone line extending from the second station to a second operators connecting station, spring jacks at each operators connecting station, a plug ended cord circuit at each station, and a relay at the second or interconnecting station responsive to the insertion or Withdrawal of elther plug in the corresponding jack for automatically connecting and disconnecting said lines respectively.

42. A telephone system comprising a telephone line extending from a first operators connecting station to a second or interconnec'tingstation, and a second telephone line extending from the second station to a second operators connecting station, a line jack and a switching jack connected to each line at its operators station, a plug ended cord circuit at each station, and means whereby when a plug is connected to its line jack connpctionis established with its near line, and a relay at the second or interconnecting station responsive to the insertion or withdrawal of a plug from the switching jack forautomatically connecting or disconnecting the two lines at the interconnecting station, respectively.

43. In a telephone system, a telephone line extending from a first operators connecting station to a second station, a second telephone line extending from the second station to a second operators connecting station, a line jack and a switching jack con nected to the first line at the first operators station, a plug ended cord circuit at said first station, means whereby when said plug is connected to the line jack connection is established with the first line, and when the plug is connected to the switching jack connection is extended over the first line to the second operators connecting station, subscribers telephones connected to each line, and means whereby the'originatin operator may signal the substations on the rst line or signal over the first line to the substations on the second line, in each case without disturbin the signals on the line not called.

44. i telephone system comprising two telephone lines terminating at a central interconnecting station, an operators connecting station on each line, said operators stations bein at different switchboards, means whereby t e operator at either line may signal on the near line or on the far line independently, and signals at the operators switchboards operated res onsive to a call from the other switchboar to indicate when it call is extended from a far line to the near 45. A telephone system "comprising two telephone lines terminating at a central interconnecting station, an operators connect-v ing station on each line, said operators stations being at different switchboards, subscribers telephones connected to each line, means where y the operator at either line station may signal the stations on the near line or the far line independently as to the lines, and signals at the operators switchboards operated responsive to a call from the other switchboards to indicate when a call is extended from a far line to a substation on the near line.

46. A telephone system including two normally telephonically unconnected telephone mally telephonically unconnected subscrib-' ers telephone lines terminating at a central interconnecting station, an operators connecting station on each line, said operators stations bein at different switchboards,

relay mechanism at the central station controlled from either operators switchboard for interconnecting said lines telephonically at said central station, and means whereby the operator at either switchboard may listen in to determine whether the far line is idle or busy.

48. A telephone system including two nor mally telephonically unconnected telephone lines terminating at an interconnecting station, an operators connecting station on one of said lines, relay mechanism at the interconnecting station common to said two lines only controlled from said operators station for interconnecting said lines telephonically at said interconnecting station, and means whereby the operator at said. connecting station may listen in to determine whether the far line is idle or busy, and means controlled over the near line whereby the operator may transmit a calling signal over the far line independent of the near line.

49. A telephone system including two normally telephonically unconnected subscribers telephone lines terminating at a central interconnecting station, an operators connecting station on each line, said operators stations being at different switchboards, subscribers telephones connected to each line, means whereby the telephones on either line may be laced in communication with the operator s connecting station on the far line, and means at the central interconnecting station operative upon response from the distant called station for interconnecting the lines tele honically.

50. A telep one system comprising a telephone line extending from an operators exchange to an intermediate interconnectin point, a second line extending from sai point to a second operators switchboard, a subscribers telephone on'the second line, a line signal at said second switchboard controlled from the subscribers telephone on the corresponding line, means at said second switchboard controlled over the two lines from the other switchboard for signaling said telephone, and means for rendering said line si al inefl'ective when said telephone signa ing means are operated.

51. A telephone system comprising a telephone line extending from a first operators switchboard to an intermediate interconnecting point, a second line extending from said interconnecting point to a second operators switchboard, a telephone on the second line, means at the second switchboard controlled from the first switchboard for signaling said telephone, a line signal at the second switchboard responsive to said telephone signaling operation, a second line signal at the-second switchboard for signaling the operator thereat from the telephone, a spring jack at the second switchboard for 20 extending connection to the lines, and means responsive to connection With said spring jack for disconnecting the two line signals.

Signed by me at Portland, county of Multnomah, and State of Oregon, in the 25 presence of two witnesses, this 10th day of June, 1915.

HERBERT M. FRIENDLY.

Witnesses ARCHIBALD E. BURNS, M. L. KNAPP. 

